Lifejacket

ABSTRACT

There is disclosed an inflatable portion for a life-jacket, for example of the type intended for use by aviators, which includes an outer envelope and an inner bladder, the envelope comprising at least one extendable part which extends when there is a given differential between the pressure inside and outisde the inflatable portion to increase the envelope volume and thereby limit the pressure differential. In one embodiment which is disclosed the extendable part consists of an elastic panel, for instance a panel fabricated from elastic yarn. In other embodiments the outer envelope has at least one flap which may be folded against another portion of the envelope and there releasably secured to form an extendable part which when unsecured provides increased envelope volume. By using such inflatable portions the disadvantageous effects of ambient conditions tending to increase the pressure differential are avoided without loss of gas therefrom. Also disclosed is the application of the same principle to lifesaving appliances in general, and to cases where the use of an envelope is dispensed with.

United States Patent 11 1 Hawkins Oct. 2, 1973 I 1 LIFEJACKET James Mitchell Hawkins, Ashton-under-Lyne, Lancashire, England [75] Inventor:

[22] Filed: Nov. 1, 1971 [21] Appl. No.: 194,227

[30] Foreign Application Priority Data Mar. 11, 1971 Great Britain 6,638/71 [52] US. Cl ..9/342 [51] Int. Cl. B63c 9/14 [58] FieldofSearch ..9/3ll345 [56] References Cited UNITED STATES PATENTS 2,538,775 1/1951 Goldsmith... 9/316 3,345,657 10/1967 Peeler et al 9/316 3,354,480 11/1967 Harding et al. 9/316 3,441,963 5/1969 Steinthal 9/314 3,497,889 3/1970 Mellin, Jr. et al. 9/340 Primary ExaminerMilton Buchler Assistant ExaminerPaul E. Sauberer Attorney-Kurt Shaffert et al.

[57] ABSTRACT There is disclosed an inflatable portion for a life-jacket, for example of the type intended for use by aviators, which includes an outer envelope and an inner bladder, the envelope comprising at least one extendable part which extends when there is a given differential between the pressure inside and outisde the inflatable portion to increase the envelope volume and thereby limit the pressure differential.

In one embodiment which is disclosed the extendable part consists of an elastic panel, for instance a panel fabricated from elastic yarn.

In other embodiments the outer envelope has at least one flap which may be folded against another portion of the envelope and there releasably secured to form an extendable part which when unsecured provides increased envelope volume.

By using such inflatable portions the disadvantageous effects of ambient conditions tending to increase the pressure differential are avoided without loss of gas therefrom.

Also disclosed is the application of the same principle to life-saving appliances in general, and to cases where the use of an envelope is dispensed with.

8 Claims, 6 Drawing Figures PATENTED' 2 73 SHEET 10F 3 PATENTEDUBT lm I sum 2 or 3 LIFEJACKET This invention concerns life-saving appliances and especially, though not exclusively, life-jackets which, for example, are intended for use by aviators who may, in an emergency, need to leave an aircraft flying over water, by ejection, at high altitudes, and which comprise an inflatable portion and means whereby this portion is inflated by a fixed charge of gas stored in a pressure bottle associated with the life-jacket (hereinafter called A life-jacket of the type referred to).

It is important that a life-jacket, in order adequately and comfortably to support the wearer in the water (and it should be borne in mind that the wearer may be unconcious), should have adequate buoyancy and should be effective to turn the wearer so as to face oncoming waves and to provide support for the wearers head so that pressurised mouth is held clear of the water. This is true no less in the case of the life-jacket of the type referred to and among the desiderata necessary fully to achieve this is that the inflatable portion should be inflated by sufficient gas and to a pressure lying within a certain range, for example one-quarter p.s.i.g., to one p.s.i.g. However because of the possible extremes of ambient conditions in which the inflatable portion may be inflated, it is difficult to guarantee these desiderata. For example if a life-jacket of the type referred to is designed, for effectiveness, to be pressured at l p.s.i.g., at 5 C at sea level then, if as could well be in certain geographical regions, the inflatable portion were inflated and subject to a temperature of say 65 C at sea level, then the pressurisation would be increased to 4 p.s.i.g., which would seriously impair its ability comfortably to support the wearers body in the proper position and would strain the inflatable portion considerably, if not burst it. Again, if the inflatable portion were inflated, as again could well be, at a high altitude where the pressure was say p.s.i.a., then the differential pressure effective in the inflatable portion would increase to around 6 p.s.i., and the inflatable portion would, as in the former case, be subjected to considerable strain and in this case, might well burst. Whilst the provision of a relief valve to ensure that the pressure did not exceed, say, 2 p.s.i.g., would be effective whilst the ambient conditionspostulated in the two above examples persisted, it is to be noted that part of the gas charge would be lost and that this would mean, should the ambientconditions change more nearly to approach the design conditions (as would usually happen, e.g., in the case of the second example after descent has been completed), then the inflatable portion would become soft and because of gas loss, have re-.

duced buoyancy, and its effectiveness would be seriously impaired, if not completely lost.

Clearly other kinds of inflatable life-saving appliances, such as life-rafts could be subject to similar problems.

The main object of the present invention is to provide a life-jacket of the type referred to which goes some way at least to overcoming the difficulties mentioned.

According to the present invention an inflatable portion of or for a life-saving appliance, and especially a life-jacket inflatable portion adapted to be incorporated in a life-jacket of the type referred to includes at least one extendable part adapted on inflation eventually to restrict the inflated volume to a given magnitude during a period whilst the differential between the pressure inside and outside the inflatable portion is increased to reach a predetermined value but on said differential being exceeded to extend to provide additional inflatable volume and thereby limit said differential.

Such a life-jacket inflatable portion preferably in cludes an outer envelope and an inner bladder, said envelope comprising at leastone such extendable part. The extendable part may consist of an elastic panel, or a portion of the envelope which may be folded in the form of a flap against another portion thereof and there releasably secured thus forming an extendable part, the flap when unsecured providing increased envelope volume. The flap may be releasably secured by means of complementary strips of hook and loop fastening material sold under the Registered Trade Mark VEL- CRO by Selectus Limited of Biddulph, England.

The invention will now be described further by way of example only, with reference to the accompanying drawings, in which:

F161 is a perspective view of a stole-shaped inflat able portion for a life-jacket, constructed according to the invention and in normal inflated condition;

FIG.2 is a detail perspective view of the stole of FIG.1 in a state in which the pressure is increasing above normal;

FIG.3' is a detail perspective view of FlG.l with extra volume provided according to the invention on still further increase in pressure;

FIGA is a perspective view of another stole for a lifejacket, also constructed according to the invention, in inflated condition and showing how extra volume is provided;

FIG.5 is a view similar to FIG. 4 of yet another form of stole, and

FIG.6 is a view similar to FlG.4 showing a still further form of stole.

Referring first to FIG], the stole 10 is of basically conventional form, comprising an outer envelope of relatively inextensible fabric and a bladder fitted therewithin, and is for attachment within a life-jacket of the type referred to. (The remainder of the life-jacket which is of well-known construction, see our British Patent Specification No. 1046696 is not shown in the interest of clarity.) At each lower end the envelope is provided with a single thickness extension 12. Across this extension 12 is provided a piece 14 of hooked VELCRO material. Some way from each end of the stole is provided a piece 16 of looped" VELCRO material. The bladder is sized so as to be capable of accommodating the charge of gas when expanded due to expected extreme ambient conditions, and at a suitable working pressure.

When the stole 10 is packed for storage within the life-jacket the pieces l4, 16 are pressed together so that each lower end of the stole 10 is folded over in the form ofa flap. On inflation of the bladder within the stole 10, the pieces l4, 16 are designed to hold the flaps secured provided the internal pressure does not rise above a pre-determined value (in FIG.1 the pieces 14, 16 are shown slightly apart at one end for illustrational purposes only.) However, if the pressure for any reason begins to exceed this value the pieces 14, 16 begin to separate (FlG.2) and at another predetermined value will part entirely (FIG.3) thus releasing the flaps which then provide additional volume so that the bladder may expand further and the pressure therewithin be reduced. In this way the risk of the stole bursting in extreme ambient conditions such as those previously mentioned is reduced or eliminated, without loss of any of the gas charge. The fact that no loss of gas occurs ensures that there is no loss of buoyancy. Thus the first of the dcsiderata previously mentioned is always ensured. The second dcsideratum is lost only if ambient conditions change towards normal after release of the flaps but of course, provided the wearer is conscious the flaps can be resecured, or the stole inflated further by mouth.

Although the embodiment described is designed to operate to give increased stole volume automatically as required, a manually operable version is not excluded from the scope of the invention.

Thus, in a very simple and inexpensive manner, impairment of the effectiveness of the life-jacket is, to a significant degree at least, prevented. As far as a relief valve is concerned, it is to be noted that apart from the fact that gas is lost, such valves are expensive, do not operate within very close pressure tolerances and are subject to faults. None of these considerations apply to the constructions of the present invention.

Referring to FIGA a similar stole is shown, but two flaps 18 are provided at the sides thereof instead of at the ends.

In the embodiment of H65 a single flap 20 is provided at that portion of the stole which passes round the neck of the wearer.

FlG.6 shows a stole which does not involve the provision of flaps. In this case a panel 22 extends the whole way around the fabric envelope and is of an elastic nature, for example being fabricated from elasticated yarn. This panel 12 will allow the envelope,and thus the bladder, to expand if the pressure within the bladder should exceed a certain value. This type of construction has the further advantages that (a) the pressure can more accurately be controlled, as the panel 22 will continuously extend as the bladder pressure tends to increase, and (b) the panel 22 will automatically contract as the pressure tends to fall thus avoiding the need for any action on the part of the wearer as, say, extreme ambient conditions revert to more normal conditions.

All the embodiments illustrated include an envelope and bladder but the use of an envelope may in suitable circumstances be dispensed with. In such cases the bladder will be provided with for example, one or more extendable flaps or have secured thereto at suitable points internally or externally, strap-like members of elasticated fabric.

I claim:

1. An inflatable means adapted to be incorporated in a lifejacket of the type referred to and comprising an outer envelope and an inner inflatable bladder, said envelope including at least one extendable part adapted on inflation eventually to restrict the inflated volume of said bladder to a given magnitude during a period whilst the differential between the pressure inside and outside said bladder is increased to reach a predetermined value, but on said differential being exceeded to extend to provide additional inflatable volume and thereby limit said differential.

2. An inflatable means as claimed in claim 1 in which each extendable part consists of an elastic panel.

3. An inflatable means as claimed in claim 2 in which said panel is fabricated from elastic yarn.

4. An inflatable means as claimed in claim 1 comprising means whereby a portion of the envelope may be folded in the form of a flap against another portion thereof and there releasably secured thus forming an extendable part, said flat when unsecured providing increased envelope volume.

5. An inflatable means as claimed in claim 4 comprising two flaps, one at each end of the envelope, which is in the form of a stole.

6. An inflatable means as claimed in claim 5 in which the two flaps are of equal extent.

7. An inflatable means as claimed in claim 4 in which the means for releasably securing the or each flap is adapted when in the secured position automatically to separate on given differential being exceeded.

8. An inflatable means as claimed in claim 7 in which said means for releasably securing each flap consists of complementary strips of hook and loop" fastening material, such as that sold under the Registered Trade Mark VELCRO.

"UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No- 3 1 2 Dated October 2, 1973 I t James Mitchell Hawkins It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the Specification:

Column 1, line 18 "pressurised" should be'-- the Signed and sealed this 19th day ofiMarch l974.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. C. MARSHALL DANN Attesting'Officer Commissioner of Patents :ORM po'mso (wsg) USCOMM-DC scan-ps9 U.S. GOVERNMENT-PRINTING DFFICE! I969 0-366-33l 

1. An inflatable means adapted to be incorporated in a lifejacket of the type referred to and comprising an outer envelope and an inner inflatable bladder, said envelope including at least one extendable part adapted on inflation eventually to restrict the inflated volume of said bladder to a given magnitude during a period whilst the differential between the pressure inside and outside said bladder is increased to reach a predetermined value, but on said differential being exceeded to extend to provide additional inflatable volume and thereby limit said differential.
 2. An inflatable means as claimed in claim 1 in which each extendable part consists of an elastic panel.
 3. An inflatable means as claimed in claim 2 in which said panel is fabricated from elastic yarn.
 4. An inflatable means as claimed in claim 1 comprising means whereby a portion of the envelope may be folded in the form of a flap against another portion thereof and there releasably secured thus forming an extendable part, said flat when unsecured providing increased envelope volume.
 5. An inflatable means as claimed in claim 4 comprising two flaps, one at each end of the envelope, which is in the form of a stole.
 6. An inflatable means as claimed in claim 5 in which the two flaps are of equal extent.
 7. An inflatable means as claimed in claim 4 in which the means for releasably securing the or each flap is adapted when in the secured position automatically to separate on given differential being exceeded.
 8. An inflatable means as claimed in claim 7 in which said means for releasably securing each flap consists of complementary strips of ''''hook'''' and ''''loop'''' fastening material, such as that sold under the Registered Trade Mark VELCRO. 